Flashing light signal



March 21, 1933. s. M. DAY 1,902,799

FLASHING LIGHT SIGNAL Filed Sept. 1, 1926 I Gr mm;

' Patented 21 1933 UNITED STATES PATENT OFFICE SALISBURY I. DAY, 01 ROCHESTER, NEW YORK, ASSIGNOB 'ro GENERAL RAILWAY SIGNAL COMPANY, OF ROCHESTER, NEW YORK I'LABHHQ'G LIGHT SIGNAL Application filed September 1, 1928. Serial No. 182,898.

This invention relates in general to a flashing light signal and has more particular reference to such a signal operated from an alternating current source of energy.

At points where highways cross railways it is often desirable to provide light signals, and preferably flashing light signals to more readily attract attention, in order to warn users of the highway when a train is near the crossing. This may be accomplished by controlling the lighting circuit of the light signal, by a track relay connected in the usual manner in a detector track circuit adjacent the crossing so that occupancy of the detector track section will de-energize the track relay and thus control the lifghting circuit of the signal. This means 0 control is set forth in more detail in applicants co-pending application, .Ser. No. 602,063, filed November 20, 1922 to which attention is directed.

In many .cases an alternating current source of energy may already be at hand at the intersections, in which event it is of course, desirable that the light signal system be operated from' such alternating current source.

While various means may be used for automatically controlling. the lighting circuit through the light signals in order to produce a flashing signal, it has been found most desirable to use control means employing direct current translating devices, and preferably tractive typerela s such for example as in Dodgsons U. S. atent 896,808, August 25, 1908. It is in the interest of economy both in initial cost and in maintenance to use such tractive type relays since they are much cheaper than alternating current relays, are

of order, require less expense in maintenance and are more trustworthy in operation.

If the attempt be made to operate such tractive type relays with an alternating cur- 5 rent, even though it has a frequency of 60 cycles, a continuous chattering of the relay armature results, which causes an imperfect operation of the light signals. Also, such an attempt would result 'in prohibitive iron losses, and very large current consumption simpler in construction, less likely to get out for even very imperfect operation of the relays.

It therefore, becomes most desirable, at times to operate a flashing light signal having controllin means employing tractive type relays, rom an alternating current source of energy, and .it is with this object in View that the present invention provides means, including properly arranged rectifying apparatus, whereby this can be accompllshed.

Further objects, purposes and characteristic features of the invention will appear as the description progresses.

In order that the invention may be more readily understood the accompanying draw- 4 ing including a single figure, shows one physical embodiment o the present invention in a wholly diagrammatic manner.

In the drawing an alternat' source of energy is shown at 1 to whlch is connected a line transformer LT. A track relay T is connected to a detector track circuit in the usual manner (not shown in the drawing) so that its finger 7 will drop away when its detector circuit 1s occupied by a train. A flashing light signal is s own at S and includes ight units 2 and 3 placed back to back and positioned to be visible in either direction along the highway which is to be protected.

Two control relays are shown at F and F, which are cross-connectedas will appear below, so as to automatically control a lighting circuit for the signal S, which lightin circuit includes contact fingers 4 and 5 o relay 1?. Connected in the energizin circuits of the relays F and F is a recti ing device R of any desired and suitable kind, and such circuits also include contact finger 7 of the track relay T.

Both the lighting circuit for the signal S, and the circuits for the control relays, are energized from the secondary of the transformer LT, an adjustable lead 6 being provided for regulating the voltage across the 95 relays to a proper operating voltage. The control relays F and F are preferably direct current relays of'the tractive type Y which are provided with a high inductance In order to make them slow acting both in pick- 71 current 7 I up and drop-away characteristics. This may be accomplished in any desired manner, such as by means of a short-circuited copper band tion of the relay, while the drop-away of the finger also lags an appreciable time behind the de-energization of the relay.

Operatz'ow-Assflming the various parts to be in the position shown in the drawing, and that the detector track circuit of relay T is occupied, the relay T will be de-energized and its contact finger 7 will drop thus completing an energized circuit for relay F which can be traced as follows :-from the secondary of transformer LT, wires 8 and 9, rectifier R, wire 15, contact finger and back contact 7 of relay T, wire 10, contact finger and back contact 11 of relay F wire 12, the coil of relay F Wire 13, adjustable contact 6, and back to the secondary of transformer LT.

Energization in this manner of relay F causes it to pick up its finger 14 which results in closing a circuit energizing relay F which may be traced as follows :from the secondary of transformer LT, wires 8 and 9, rectifier R, wire 15, contact finger and back contact 7 of relay T, wires 10 and 16, contact finger and front contact 14 of the relay F wire 17, the coil of relay F wire 18, adjustable contact 6 and the secondary of the transformer LT.

Energization of relay F causes the pickup of its fingers 4, 5 and 11. The fingers 4 and 5 in picked up position close the lighting circuit through the signal lamps 2 and 3 which may be traced as follows :the secondary of transformer LT, wires 8 and 19, then in parallel through wires 20 and 21, lamps 2 and 3, and wires 22 and 23, wire 24, contact fingers and front contacts 4 and 5 of relay F wire 25, and back to the transformer secondary. This lighting circuit energizes the lamp filaments and gives the desired signal indication.

It will be noted however, that at the same time of closingthe lighting circuit through the lamps 2 and 3 by the pick-up of fingers 4 and 5 of relay F the relay finger 11 also picked up to cause opening of the energizing circuit through relay F as traced above. The deenergization of relay F allows its contact finger 14 to drop away to thereby open the energizing circuit for relay F as "traced above. upon becoming deenergized relay F allows its contact fingers 11, 4 and 5 to drop away and thus breaks the lighting circuit through the lamps 2 and. 3 as traced above, and bring the various parts back to their positions as shown on the drawing.

Due to the slow acting characteristic of the relays F and F an appreciable period of time elapses between de-energization of relay F and the drop away of its finger 14, and also between the de-energization of relay F and the drop away of its fingers 11, 4 and 5. It is during the period covered by these two lags, that the lighting circuit through the signal lights is closed and the filaments energized.

So long as contact finger 7 of track relay T is in its de-energized, or dropped-away, position, the above described cycle of operation will be repeated with resulting flashes of the signal lights, thus giving a flashing light signal at the crossing to be protected.

By inserting the rectifying means R as described above and shown on the drawing the current operating the circuits of the two tractive type relays, F and F is direct current, but is obtained from the alternating current source 1, which also supplies the lighting circuit for signal S with alternating current through the lighting circuit as traced above.

By means of the present invention, as illustrated in the example shown, and described above the economies are realized which result from using tractive type relays operated from an alternating current source, for controlling a flashing light circuit which is energized with alternating current.

The above specific description of one arrangement embodying the present invention is given solely by way of illustration, and is not intended in any manner whatsoever, in a limited sense. Obviously this invention can assume many different physical forms, and all such forms are intended to be included by this invention, as come within the scope of the appended claims.

I now claim 1. In an automatic railway crossing signal system, an alternating current source of energy, a flashing light signal unit, a lighting circuit for the light unit fed from the alternating current source, direct current interconnected relays constituting automatic make and break control means for the lighting circuit, and an energized circuit for the control means including the alternating current source and a rectifier in series.

2. In an automatic railway crossing signal system, an alternating current source of energy, a signal light unit, a lighting circuit for the lighting unit fed from the alternating current source, automatic control means including interconnected dependent trac-tive type relays for intermittent make and break control of the lighting circuit, and an energizing circuit for the control means including the alternating current source and a rectifier in series.

3. In a signal system for railway crossings,

an alternating current source of energy, a signal light unit, a lighting circuit for the lighting unit fed from the alternating current source, control means including cross connected, slow release, tractive type relays for intermittently making and breaking the lighting circuit, and an energizing circuit for the control means including the alternating current source and a rectifier in series.

4. In an automatic railway light signal, a light unit, an alternating current source of energy, a lighting circuit for the light unit fed from the alternating current source, direct current relay means automatically operating, when energized, to intermittently interrupt the lighting circuit, an energizing circuit for the relay means adjustably fed from the alternating current source, and a track relay contact and rectifier in series in said energizing circuit.

5. In a light signal, a light unit, an alternating current source of energy, a lighting circuit for the light unit fed from the alternating current source, two cross connected, slow acting, tractive type relays, for automatically intermittently interrupting the lighting circuit, an energizing circuit for said relays adjustably fed from the alternating current source, and a track relay contact and rectifier in series in said energizing circuit.

In testimony whereof I affix m signature. SALISBURY DAY. 

